Advantages of Die Casting
- High-speed production
- Dimensional accuracy and stability
- Tight tolerances
- Variable wall thicknesses
- Reduction in scrap
- Multiple finishing techniques
- Simplified Assembly
Die Casting Types
Aluminum alloy die casting is to pour the molten aluminum alloy liquid into the pressing chamber, and the aluminum alloy liquid flows into the mold cavity under the action of high speed and high pressure, and then cooled and solidified into aluminum alloy die casting under the action of pressure.
The products made of aluminum alloy have high dimensional precision, good surface roughness, good casting stability, and high strength. Aluminum alloy dies castings have the characteristics of durability, corrosion resistance, good toughness, high strength, high electrical conductivity, non-magnetism, lightweight, and so on.
At present, aluminum alloy die casting products are mainly used in auto parts, electronic shell, communications, motor, aviation, ships, home appliances, furniture accessories, digital shell, handicrafts, security product shell, LED lighting (lampshade), and some new energy industries, etc. Some high-performance, high-precision, high-toughness high-quality aluminum alloy die casting products are also used in large aircraft, ships, and other industries with higher requirements.
Types: ADC12, A360, A380, A383, B390, A413.
Die-casting zinc alloy is also a widely used die-casting alloy at present. Its main features are as follows.
Die-casting zinc alloy has good die-casting performance and good fluidity, which can be used for die-casting parts with thinner wall thickness, which makes up for the weight effect caused by high density. Its crystallization temperature range is small, easy to form, not easy to stick mold, and easy to demoulding. The pouring temperature is lower and the service life of the die-casting die is longer. Zinc alloy has no corrosion effect on the die chamber and die casting mold parts in the range of pouring temperature.
The shrinkage is small, so it is easy to ensure the dimensional accuracy of die castings. The comprehensive mechanical properties are higher, especially the compression resistance, and wear resistance is better.
Zinc alloy die casting surface can carry out a variety of anti-corrosion and decorative treatments, such as chemical treatment, anodizing, electroplating, electrostatic spraying, vacuum chromium plating, and so on.
Types: ZA-2, ZA-3,ZA-4,ZA-5,ZA-7,ZA-8,ZA-12,ZA-27.
The density of magnesium is 1.8 g / cm ~ 3, and that of aluminum alloy is 2.7 g / cm ~ 3. Magnesium alloy is the metal with the lowest density. The gravity of magnesium is around 2/3 of aluminum and 1/4 of iron. The phase relative strength (the ratio of strength to mass) of magnesium alloy is the highest. The specific stiffness (the ratio of stiffness to mass) is close to aluminum alloy and steel, and much higher than that of engineering plastics.
Magnesium alloy has excellent properties such as strong earthquake resistance, electromagnetic resistance, thermal conductivity, and electrical conductivity, and can be fully recycled and pollution-free. Magnesium alloy is light in weight, its density is only 1.7kg/m3, its strength is higher than aluminum alloy and steel, its specific stiffness is close to that of aluminum alloy and steel, it can withstand the certain load, good casting performance, and dimensional stability, easy to process, low scrap rate, good damping coefficient, and large vibration damping than aluminum alloy and cast iron, so it is very suitable for automobile production. Also, it has wide applications in aerospace, portable computers, mobile phones, electrical appliances, sports equipment, and other fields.
Types: AZ91b, AZ91D, AZ91HP, AM60A, AM60B
Finishing for Die casting
Vibration deburring, that is grinding deburring, its principle is to use various shapes of oilstones and dozens of kilograms of parts, together with a certain amount of polishing fluid in a drum-shaped vibration cavity to rub irregularly for removing the parts burr and ensure no damage to the parts. Finally, the parts are sorted out with a sieve, cleaned, and dried. Deburring can prepare for painting and other surface treatment processes, and greatly improve the appearance and surface quality of products.
The sandblasting process can remove the impurities such as burr, oxide scale, and stolen goods of the die casting, and achieve the effect of cleaning the surface of the die casting. The sand blasting process is often used to deal with die castings with precise design, complex shape, and low efficiency of manual treatment.
Polishing is the process of using grinding media and various tools to mechanically grind and modify the surface of the workpiece, which will lead to smoother and brighter surface polishing. Polishing is usually divided into manual polishing and manipulator automatic polishing. The robot provides a fully automatic metal polishing solution for fast and efficient surface polishing and polishing. Robots are usually equipped with a series of polishing and grinding wheels to provide a smooth and bright polishing effect.
Electrostatic spraying of powder coating uses static electricity to adsorb the powder coating on the working surface, and the powder is baked at high temperatures to form a solid coating on the working surface. Powder spraying makes the surface of the product smooth and smooth and has a coating with strong acid resistance, alkali resistance, crashworthiness, and wear resistance. the product can withstand strong ultraviolet radiation and acid rain for a long time without coating pulverization, discoloration, shedding, and so on.
Electroplating is using galvanolysis to plate other types of metals on the workpieces. It uses electrolysis to attach parts surface to metal film, thereby prevents metal oxidation (corrosion), improving abrasion resistance, conductivity reflective resistance, corrosion resistance (copper sulfate, etc.), and improving beauty, etc. Electroplating metal or other insoluble materials anode plating workpiece cathode coating metal cations are reduced to form coating surfaces on the workpiece surface. To eliminate interference from other cations, and make plating uniform and firm, an electroplating solution should be used as a plating solution containing plating metal cations to keep the concentration of metal cations unchanged.
The electrophoretic coating is a kind of coating technology in which the coating is impregnated in the water-soluble coating as an anode (anodic electrophoresis), and a corresponding cathode is set up to connect the direct current between the two poles and rely on the physical and chemical action produced by the current. A coating technique that enables the coating to be applied evenly on the coated object. The electrophoretic painting must use electrophoretic paint, electrophoretic paint is usually called water-soluble paint, electrophoretic paint and distilled water must be diluted according to a certain proportion before it can be used.
Kemal Your best choice for Die Casting Manufacturer
Kemal specializes in aluminum alloy die-casting, magnesium alloy die-casting, and zinc alloy die-casting. For 25 years, Kemal has been committed to providing the company with high-quality die-casting molds and die-casting products, as well as providing you with die-casting parts finishing and precision CNC machining.
We believe that accurate and reliable die casting molds are essential for mass production. Our mold manufacturing team will make die-casting molds suitable for your hot-chamber and cold-chamber die-casting machines with a maximum clamping force of 1250 tons.
Kemal will continue to invest in state-of-the-art machinery and technology to provide you with a consistent process, accurate assurance and labor cost reduction services.
If you are looking for high quality, cost-effective and technological innovation, aluminum die-casting, magnesium die-casting, and zinc die-casting molds and parts, we are your trusted partner.
Please contact us at 7/24/365.
DIE CASTING MOLD: THE ULTIMATE FAQ GUIDE
As a professional die casting mold maker, Kemal pays high attention to customers’ inquiries and satisfaction for each project. So we make a guide for you. We sincerely hope that it can help you a lot in learning more about die casting mold. Please contact us without any hesitation for help. We are always ready to support you.
- What is Die Casting Mold?
- What are the effects of Die Casting Mold?
- What is the structural composition of the Die Casting Mold?
- What should be paid attention to when installing the Die Casting Mold on the machine?
- How to correctly plan the craft for the Die Casting Mold?
- How many steps for Die Casting Mold manufacturing?
- How many types of Die Casting Mold equipment?
- Which material is suitable for Die Casting Mold manufacturing?
- What are the requirements for the manufacturing material of die casting mold?
- What industries are die casting molds used in?
- Which factors restrict the development of die casting mold in China?
- What are the new technologies of the surface treatment for die casting mold?
- How to maintain the die-casting molds?
- What is the invalidation way of die casting mold?
- What should be marked on the assembly plan of die casting mold?
- What are the acceptance criteria for die casting mold?
- What affects the processing costs for die casting molds?
- How many types of finishing for die casting mold?
- How to do the electrophoretic coating for die casting mold?
- What does vibration deburring mean for die casting mold?
Q1. What is Die Casting Mold?
Die casting (also called pressure die casting) is a special metal casting process. By pouring molten or semi-molten metal into the cavity of the casting machine, the metal liquid is filled into the die-casting mold cavity at high speed under high pressure, and the precision casting method is obtained through cooling and solidification. This process is somewhat similar to injection molding. Most die castings are iron-free, such as zinc, copper, aluminum, magnesium, lead, tin, and lead-tin alloys and their alloys. The die-casting mold used is called die-casting mold.
Q2. What are the effects of Die Casting Mold?
The important role of die casting mold in the die casting production process is:
1.To determine the accuracy of the shape and size of the casting;
2.To affect the efficiency of operation;
3.To affect the quality of the casting when taken out (such as defamation);
4.The fixed gate system (especially the gate location) determines the filling condition of the molten metal;
5.The predetermined overflow system affects the molten metal’s filling conditions;
6.The strength of the mold sets the limit for the maximum injection pressure;
7.Control and adjust the heat balance of the die casting process;
8.The quality of the mold forming surface not only affects the casting quality, but also affects the coating spraying cycle, and affects the difficulty of taking out the casting as well.
Q3. What is the structural composition of the Die Casting Mold?
Usually, a die casting mold is composed of fixed mold and movable mold.
Fixed mold: is fixed on the fixed mold mounting plate of the die-casting machine, with a sprue connected to the pressure chamber or nozzle;
Movable mold: is fixed on the mounting plate of the die-casting motorized mold, and when the mold is opened and closed with the movable mold mounting plate, the mold is closed to form the cavity and the casting system, and under high pressure, the liquid metal fills the cavity; when the mold is opened, the mold and the fixed mold is moved separately, and the casting is set to be pushed out on the ejection mechanism on the movable mold.
Q4. What should be paid attention to when installing the Die Casting Mold on the machine?
(1)Frequently check the mold lifting eye bolts, screw holes, and lifting equipment to guarantee the safety of operator, equipment, and molds during operation.
(2)Check regularly the force tolerance of the big bar for the die-casting machine, and adjust it when necessary.
(3)The mold installation location should meet the design requirements, and the distance between the mold expansion force center and the die-casting machine should be as small as possible, so the force from the big bar can be more uniform.
(4)During operation, the pressure plate and pressure plate bolts should have adequate strength and precision to prevent loosening. There should be sufficient pressing plates, preferably on all sides, and no less than two on each side.
(5)Large molds should have mold brackets to protect the mold from sinking, dislocating, or falling in the process of usage.
(6)Before mold installing, wiping the machine mounting surface and mold mounting surface completely. Check whether the length of the ejector rods is reasonable, whether all ejector rods lengths are the same, there should be at least 4 ejector rods, and they should be placed in the specified ejector rod holes.
(7)Adjustment after mold installation, including the clamping tightness, as well as injection parameters: fast injection speed, injection pressure, slow injection stroke, fast injection stroke, boost pressure, punch follow-up distance, eject stroke, eject reset time, etc. After the adjustment, put soft objects such as cotton silk in the pressure chamber, do two simulations of the entire injection process, and check if the adjustment is good or not.
(8)Molds with larger core pulling or molds that need to be reset may also need to be installed separately from the movable and fixed molds.
(9)The tightness of the cooling water pipe and installation should be guaranteed.
(10)Before production, we need to confirm the mold completeness. The mold should be correctly connected to the oil pipe and switch circuit, etc., and not to expose the metal of the conductive part, and before the operation, we should choose the control program.
(11)The mold clamping needs to be adjusted to a suitable distance between the movable half and the fixed half, stop the machine, and put the mold preheater between them.
(12)Confirm that there is no obstacle in each cooling water path.
(13)For molds with sliders above the mold and on the left and right sides, we should install suitable springs to fix the mold.
(14)The mold with an inverted pull device must be equipped with an inverted rod, and the thimble must be returned after being ejected, otherwise, the mold cavity will be damaged.
(15)For molds with orientation requirements for cores or shared cavities, we have to confirm the correctness of the core.
(16) For molds with slider cores, core pulls, and complex structures, they should be fully preheated (the mold cavity must be oiled before preheating the mold) before production.
Q5. How to correctly plan the craft for the Die Casting Mold?
The die-casting process reflects the technical level of a die-casting factory, which can produce die-casting molds and products that satisfies customers’ needs at the lowest cost. Therefore, it is very necessary to formulate the correct die casting process.
(1)To confirm the optimal production rate and specify the injection cycle time.
(2) Work out the correct die-casting parameters.
(3) Astringent and detailed spraying process must be taken at the time when using water-based paint.
(4) To schedule the correct mold cooling plan according to the actual die casting mold.
(5) Offering different lubrication frequencies for different sliding parts, such as pushrods, reset rods, punches, guide sleeves, guideposts, and so on.
(6) For each die-casting part, we need to formulate die-casting operating procedures, train and supervise die-casting staff to operate based on the procedures.
(7) Determine the workable preventive maintenance cycle of the mold on the basis of the mold complexity and degree.
(8) In line with the complexity of the mold, the degree of new and old, and the degree of sticking risk, we shall work out the module stress relief cycle (usually 5000 to 15000 mold times) and if the surface treatment is needed or not.
Q6. How many steps for Die Casting Mold manufacturing?
The traditional die casting process mainly includes four steps: mold preparation, filling, injection, and shakeout, which are the foundation for different updated die casting processes as well. In the preparation process, people spray a lubricant into the mold cavity. The lubricant helps not only to control the mold temperature but also to de-mold the casting. After that, the mold can be closed and the molten metal could be injected under high pressure from 10 to 175 MPa. And the pressure will be kept until the casting solidifies when the molten metal is filled. Then all castings will be pushed out by the pushrod. Besides, for multi-cavity molds, multiple casting will be made during each casting process.
The shakeout process needs to separate the residues, such as runners, gates, flash and so on, which usually is finished by a special trimming die.
Q7. How many types of Die Casting Mold equipment?
In general, there are two types of machines for die casting mold. They are hot chamber die casting machines and cold chamber die casting machines.
(1) Hot chamber die casting machine
Hot chamber die casting, also called gooseneck die casting, has molten liquid and semi-liquid metal in the metal pool, which fills the mold under pressure. At the start of the cycle, the machine piston is in a contracted state, and the molten metal will fill the gooseneck. The metal is squeezed by pneumatic or hydraulic pistons and filled into the mold.
(2) Cold chamber die casting machine
Cold chamber die casting is suitable for metals that cannot be used in hot chamber die casting processes, such as magnesium, aluminum, copper, and zinc alloys with high aluminum content. This process requires melting the metal in a separate pot. When the molten metal reaches a certain amount, it will be moved to an unheated injection chamber. By hydraulic or mechanical pressure, these metals are injected into the mold.
Q8. Which material is suitable for Die Casting Mold manufacturing?
In general, there are 4 kinds of material for manufacturing a die casting mold. They are magnesium alloys, aluminum alloys, copper alloys, and zinc alloys.
1.For magnesium alloys, the commonly used grades are ZnAl4-1, ZnAl4-0.5, and ZnAl4.
2.For aluminum alloys, the commonly used grades are ZL101, ZL102, ZL103, ZL104, ZL105, ZL301, ZL302, and ZL401.
3.For copper alloys, the most commonly used grade is ZM5.
4.For zinc alloys, the popular grades are ZHSi80-3, ZHPb59-1, ZHAl67-2.5, and ZHMn58-2-2.
Q9. What are the requirements for the manufacturing material of the die casting mold?
For the manufacturing material of die casting mold, 5 requirements are important to be satisfied.
1.Material should be of high strength, hardness, anti-tempering stability, and thermal shock toughness under high temperature.
2.Material should be of excellent thermal conductivity and thermal fatigue resistance.
3.Material is not easy to oxidize and resistant to adhesion and corrosion of liquid metal.
4.Material should be of a small thermal expansion coefficient.
5.Material has small heat treatment deformation and excellent hardenability.
Q10. What industries are die casting molds used in?
Die-casting molds and products are widely used in our daily life, and they have been used in hardware and the entire mechanical and electronic industries. Moreover, their uses have become wider and wider. The detailed application ranges of die-casting molds and products mainly include internal combustion engine production, automotive manufacturing, oil pump manufacturing, motorcycle manufacturing, motor manufacturing, construction, hardware, equipment, machine tools, transmission machinery manufacturing, ships, aerospace, automobiles, locomotives, electronics, computers, electrical appliances, lamps and many other fields.
Q11. Which factors restrict the development of die casting mold in China?
The main reasons restricting the development of China’s die casting mold industry are as follows.
Firstly, there are still lots of disadvantages in using raw materials in domestic die-casting molds.
Secondly, our related technology falls behind many other countries, which is a great obstacle to the development of China’s die-casting mold industry.
Thirdly, the supporting system of China’s die-casting mold industry is still imperfect.
Q12. What are the new technologies of the surface treatment for die casting mold?
Relying on the new high-tech technology, it is possible to develop the process of die casting molds. At the same time, this also puts forward higher and more demanding requirements on the mold itself. Only with stronger mechanics, higher die-casting efficiency, longer service life, more accurate die-casting precision, etc., can we have more precise surface treatment on the die-casting molds.
So far, the commonly used new surface treatment techniques for die casting molds include traditional improvement techniques, plating techniques and surface modification techniques.
1.The traditional technology refers to treat the die-casting mold with a thermal process, that is, quenching and tempering are used to form the surface of the die-casting mold.
2.The plating technique is a way to treat the mold with a coating.
3.The technology of surface modification techniques is using physical or chemical methods to change the physical and chemical properties of the mold surface to make it easier to satisfy production needs.
Q13. How to maintain the die-casting molds?
As we all know, no matter which types of molds, we need to do the maintenance of them. And here are some tips to maintain the die casting molds for your reference.
1)Before operating a new die casting mold, we suggest you do the surface strengthening treatment.
2)You should do the first maintenance when the die casting mold comes to its 5,000 – 10,000 shots.
3) When the die casting mold reaches 30,000 shots, you should do the second maintenance.
4)The third maintenance shall take place at the time when the die casting mold comes to 50,000 shots.
Q14. What is the invalidation way of die casting mold?
The major invalidation ways of die casting molds are: cracking, corrosion, erosion, adhesion, and thermal cracking.
Corrosion: is the surface wear caused by high-temperature liquid alloy and high-speed friction of the die casting mold.
Erosion: refers to the chemical reaction that occurs between the molten alloy and the die casting mold surface.
Adhesion: means the adhesion between the die-cast product and the mold, which leads to surface damage to the product and mold.
Thermal cracking: When the die-casting mold is produced, the mold is repeatedly stimulated by cold and heat, then the small cracks occur on the die casting mold surface.
Q15. What should be marked on the assembly plan of die casting mold?
The following points should be marked on the assembly plan of the die casting mold.
1.The largest sizes of the die casting mold.
2.The suggested die casting machine type.
3.The proposed inner diameter, specific pressure, or nozzle diameter of the pressure chamber.
4.The smallest opening stroke.
5.The schedule of the ejector system.
6.The injection system and major dimensions of the casting part.
7.The specifications, quantity, and process of the accessories related to the die casting mold.
8.Remarks about the movement of the special mechanism.
Q16. What are the acceptance criteria for the die casting mold?
1)Appearance inspection: mold label and details are complete and correct and should include basic information such as mold number, press model, punch diameter, moving and fixed mold weight, and supplier information. The identification of different numbers is clear and complete; the appearance is clean and no visible marks.
2)Dimension check: check all dimensions to guarantee successful installation with the nominated machine.
3)Inspection of mold material and heat treatment hardness, and provide the material certificate and heat treatment report.
4)Ensure that the fit clearance of each movable part meets the customer’s technical requirements.
5)The critical dimensions of the casting are all qualified based on the tolerance requirements of the technical drawing.
6)Parting surface cooperates with coloring inspection to guarantee reliable mold sealing.
7)The lifting screw holes of all parts are complete and the lifting is off balance.
8)Check the pressure of the cooling water circuit to be without leakage.
9)Check the slag discharge and drainage holes under the slider.
10)The quick-change plug of the pin is complete and reliable, and confirm the trace of the ejector pin is in line with the requirements of the drawing.
11) Check whether the wearing parts are complete and the serial number is complete and correct.
Q17. What affects the processing costs for die casting molds?
Here are 4 aspects that affect the processing costs of die casting molds.
For die casting molds with different structures, the manufacturing process is different accordingly. Some molds can be solved by mold design, and some can also be processed by subsequent post-processing.
Even for the same mold, the prices can be totally different because of choosing different tonnages of molding machines.
Therefore, we should think it over before making a decision on the supplier.
Q18. How many types of finishing for die casting mold?
Here are several types of finishing for die casting mold, such as vibration deburring,
sandblasting, polishing, powder coating, electroplating, as well as electrophoretic coating, etc.
Q19. How to do the electrophoretic coating for die casting mold?
The electrophoretic coating is a coating technology (anodic electrophoresis) in which the coating is immersed in the water-soluble coating as the anode, and the corresponding cathode is established to connect the direct current between the two poles and relies on physical and current chemical effects. A coating technology that makes the coating evenly spread on the coated object. Electrophoretic paint must use electrophoretic paint. Electrophoretic paint is usually called water-soluble paint. Electrophoretic paint and distilled water must be diluted in a certain proportion before use.
Q20. What does vibration deburring mean for die casting mold?
Vibration deburring, that is grinding deburring, its principle is to use various shapes of oilstones and dozens of kilograms of parts plus a certain amount of polishing fluid in a drum-shaped vibration cavity to rub irregularly with the oilstone, to remove the burr of parts and ensure no damage to the parts. Finally, the parts are sorted out with a sieve, cleaned, and dried. Deburring can prepare for painting and other surface treatment processes, and greatly improve the appearance and surface quality of products.